1. Field of the Invention
The present invention relates to a technology for providing service from a service providing device to a service user terminal via the service relaying apparatus.
2. Description of the Related Art
There had been technologies to realize the Internet services by a combination of communication line services provided by communication carriers and application services provided by service providers. In such conventional technologies, application software corresponding to an application service to be used is installed on a service user terminal, so that the application software communicates with an application server that provides the application service using a predetermined protocol. Thus, various types of applications become available on the service user terminal device.
It has becomes an important issue how to assure quality of communication for the application services. For example, Japanese Patent Application Laid-open No. 2004-341583 discloses a method for controlling quality of communication. According to the conventional method, passing packets are sorted by identifying transmission destinations and applications based on the destination addresses and the port numbers of the packets in a communication relaying apparatus such as a communication gateway, so that the quality of communication between application software and the application server can be assured.
However, with conventional technologies including the one mentioned above, a protocol related to the communication is exchanged between the service user terminal and the application server. The communication relaying apparatus only performs network layer processing to transfer communication packets.
Accordingly, every time a new application service starts being used, application software corresponding to the application service needs to be installed on the service user terminal and appropriate settings need to be made. This requires not only the cumbersome operation of installing the application software and making the appropriate settings, but also, in some cases, specialized knowledge for installing and setting up the application software. Consequently, it is difficult to start using a new application service.
Further, due to the recent development in ubiquitous computing, various types of information appliances having a microcomputer have become available. It is not possible for a user to add and install new application software on the information appliance, unlike personal computers to which users have been able to add new application software. Furthermore, it is often the case that personal computers are connected to intranets, and installation of new software is restricted for security reasons.
Thus, a problem arises where it is impossible or difficult to use a new application service if it is impossible or difficult to install application software corresponding to the new application service on a service user terminal.
With regard to assuring the quality of communication in the application service, it has not been possible, with the conventional technologies, to block unauthorized access from a service user terminal because the communication relaying apparatus only transfers communication packets and is not at all involved with the application protocol.
Further, when the application software required in the communication of the application service is managed for each service user terminal, while the communication relaying apparatus only relays communication packets, if a failure occurs, it is difficult to identify a cause of the failure. This also makes it difficult to assure the quality of communication in the application service.